Means for correctly setting relieved taps in thread-finishing machines



April 19, 1932. R. E. FLANDERS 1,854,184

MEANS FOR CORRECTLY SETTING RELIEVED TAPS IN THREAD FINISHING MACHINESFiled Dec. 6. 1922 2 Sheets-Sheet 1 April 1932- R. E. FLANDERS 1,854,184

MEANS FOR CORRECTLY SETTING RELIEVED TAPS IN THREAD FINISHING MACHINESFiled Dec. 6. 1922 2 Sheets-Sheet 2 Illlllf Patented Apr. 19, 1932 RALPHE. FLANDEBS, OF SPRING-FIELD, VERMONT, ASSIGNOR 'I'O JONES & LAMSONMACHINE COMPANY, OF S?RINGFIELD, VEEMON '1, A CORPORATION OF VERMONTMEANS FOR CORRECTLY SETTING RELIEVED TAPS IN THREAD-FINISHING- MACHINESApplication filed December 6, 1922. Serial No. 605,198.

This invention relates to means and mechanism by which relieved taps maybe properly located in a grinding machine or other thread finishingmachine so that the tool may prop- 5, erly engage the threads and yetwherein the periodic relative retraction between the tap and the toolmay be caused to take place in correct relation to the flutes of the tapwith out requiring that the flutes be formed in any fixed relation tothe threads. For this purpose the angular relation of the flutes andrelieving action, which is fixed may be determined and the tap so fixedto its rotational driving mechanism regardless of whether or not thetool properly engages the threads, and

then the tap and tool may be adjusted relatively axially of the tapuntil the tool is properly related to the threads. The tap may then begiven its rotating and traversing motion relative to the tool in theusual manner with full assurance that the threads will he correctlyfinished and that the relief will be properly related angularly to theflutes.

In order to carry out this method the work and tool-carrying mechanismof the finishing machine are relatively adjustable axially of the workindependently of their relative traversing movement, and in order toinsure that this adjustment be correct before the tap is placed in themachine the adjustment is indexed and an indicating devicecorrespondingly indexed is employed for testing each individual tapbefore it is placed in the machine. The machine index having been set tocorrespond with the index of the testing device set for any particulartap, the machine is then in proper adjustment to correctly finish thethreads of that tap.

For a more complete understanding of this invention, together withfurther objects and advantageous details and combinations of parts,reference may be had to the accompanying drawings in which Figure 1 is atop plan of the testing indicator device by means of which the drivingdog is correctly related to the tap for the relieving action and thesetting of the finishing machine for proper engagement of the tool withthe tap is indicated.

Figure 2 is a side elevation of the same.

Figures 3 and 4 are detail sections on lines 3-3 and M, respectively, ofFigure 1.

Figure 5 is a fragmentary front elevation partly in section of agrinding machine hav- 7 ing an indicator thereon which may be setaccording to the indication obtained from the testing device and which,when set, insures the correct relation of the grinding wheel to thework.

The finishing machine may be of any suitable type but for the purpose ofillustration to this figure at 1 is indicated a traversing work carriageslidably supported on a base 2. This work carriage supports live anddead centers 3 and 4 between which the tap, shown at 5, may besupported. At 6 is indicated a grinding wheel having a grinding faceshaped to the contour desired between adjacent threads of the tap. Thedead center 4 is caused to move the tap laterally relative to thegrinding wheel 6 in timed relation to its rotation in order to cause adeeper cut to be made progressively back from the cutting edges of thetap defined by one side of each of the usual flutes, these flutes beingindicated at 7 As shown the center 4: is supported in a block 10 havinga hemispherical face seated in a disk 11 which is made fast by bolts 12to a sleeve portion 13 through which the center projects. This center lis given a gyratory motion within the sleeve, this motion being effectedby means of an eccentric mounting at its outer end which is driven intime with the rotation of the work by means of change gearing indicatedat 14. Details of this mechanism are shown in the patent above referredto and further explanation is believed unnecessary in the present case.The live center 3 carries a face plate 20 through which rotative drivingmay be imparted to the tap by means of a lathe dog or other suitableelement 21.

In order that the grinding wheel may prop- IOU erly follow the threadsof the tap it is necessary that the tap and wheel be traversedrelatively as the tap rotates. F or this purpose the carriage 1 may betraversed by means of an edge cam driven in time with the ro tation ofthe tap which engages a cam roller 26 fixed to a bracket 27 having anoperative connection to the carriage 1. The roll 26 is held in contactwith the cam 25 in oroer to impart a return traverse by means of aspring 28 engaging a bracket 29 extending from the carriage at one endand a bolt 30 extending from the base 2 at its other end. As will latermore clearly appear it is necessary to provide for adjusting the tap andtool axially of the tap to provide for a proper en gagement of the toolwith the tap threads of the different taps when the tap is correctlypositioned to cause the relieving to take place in proper relation tothe flutes. For this purpose the bracket 27 is carried by a shaft 35,being threaded thereon between a pair of brackets 36 and 37, dependingfrom the carriage 1. By rotation of the shaft it is evident that thebracket 27 may be moved relative to the carriage 1 so as to impart atraverse of the carriage relative to the wheel 6 independent of thetraverse by means of the cam 25 which is timed with the tap rotation. Inorder to determine the proper setting of the bracket 27 relative to thecarriage the shaft has fixed thereon an indicating wheel or disk 39having graduations marked thereon with which cooperates a fixed indexfinger 390 this being in elfect a micrometer adjustment. At the outerend of the shaft 35 may be fixed a handle 38 by which it may be rotated.

Referring now to the indicating device for determining the propersetting of the indicator 39 on the machine so that the tap and grindingwheel may be correctly related, this device comprises an entirelyseparate mechanism from the grinding machine, and which is shown inFigures 1 to 4 inclusive. Referring to these figures, 40 indicates asupporting plate on which are relatively adjustable lengthwise bracketblocks i1 and 42. The bracket 41 may be fixed in adjusted position bymeans of a stud 48 threaded in the block and passing through a slot e5longitudinally disposed through the plate 40, and having threaded on itslower end a tightening nut and washer 46. The block 41 has a hole orbore 4'7 horizontally disposed therein for the slidable reception of acenter 48 which has a reduced shank portion 49 extending through asmaller hole 50 concentric with the bore 47 and which forms a guidewayfor this shank. Seated within the bore l7 and surrounding the shank 49is a coil spring 51 which reacts between a shoulder 52 formed at therear end of the bore and a shoulder 53 formed on the center at the endof the reduced portion. This spring normally projects the center towardthe block 12 as far as may be permitted by a washer 54 placed thereonand held in position by a pin 55 at the opposite side of the block 41.Adjacent the center as an abutment pin 58 is adjustable axially in aperforation 59 parallel with the hole 47. This pin 58 is in position tobe engaged by the driving dog 21 which may be clamped to the tap 5adjacent the end of its shank portion which may be supported by thecenter 48. The other end of the tap is supported by a center 66, aportion of which is formed threaded as at 67 and engages a matedthreaded opening 68 in the block 42, the two centers being in axialalinement. The center 66 outwardly of the threaded portion 67 carries anindex wheel 69 grad uated in the same manner as the wheel 36 on thegrinding machine and with which c0- operates an index finger 7 O. Thisindex fin ger as shown is fixed to the top of the block 4-2 by means ofa clamping block 71 held in position by a screw 72. The index memberalso has fixed thereto a stop pin 78 with which cooperates a mating pin74 extending from the index wheel 69. ()utwardly of the index wheel thecenter 66 has pinned thereto a hand wheel 75 by which it may be rotated,the hand wheel and the indexing disk being preferably clamped inposition between a flange 76 on the center and a nut 7 7 threaded on thereduced extremity 78 of the center and bearing against the outer face ofthe hand wheel 75. By turning the hand wheel it is evident that thecenter 66 may be moved axially and the tap carried between this centerand the center 48 may be moved therewith, the center 48 being permittedto retract within the block 4C1 against the pressure of the spring 51 asthe center 66 is moved theretoward by turning the hand wheel.

Means are provided in this mechanism by which the driving dog 21 may befixed to the tap 5 in such angular relation to the tap that when the tapwith the dog remaining fixed thereto in the same relation are placed inposition in the grinding machine where the dog is driven from the faceplate thereof, the relieving action accomplished by the gyratory motionof the dead center of the machine shall take place properly relatedangularly to the tap flutes. For this purpose an abutment 80 has aportion 81 engaging within one of the flutes of the tap, this abutment80 being fixed by means of a screw 82 to a portion 83 projecting fromthe block This abutment block is so positioned angularly to the abutmentpin 58 that when the block 80 engages within one of the flutes of thetap and the driving dog 21 rests against the pin 58, the driving dog maybe clamped to the tap in this angular relation, which is the properangular relation to effect the desired relief of the tap threads in thegrinding machine. This having been efiected it is then necessary todetermine the axial position of the tap so as to cause the grindingwheel to properly mate the tap threads. For this purpose an elementwhich may accurately engage the tap threads is provided, this comprisinga pointed screw threaded in one arm 91 of a frame member 92; This framemember is m vable relative to the base 40 so as to permit the screw 90to be positioned axially of the tap to properly seat its point betweenadjacent threads and as shown is pivoted on a pin 93 which passesthrough the lower portion of the member 83 and also through anoppositely disposed lug 94 projecting from the block 42 in spacedrelation to the portion 83. The frame 92 has a pair of downwardlyextending ears 95 and 96 through which the pin 93 passes. Between theportion 94 and the ,ear 96 surrounding the pin 93 is positioned a coilspring 97 which acts to normally hold the ear 96 against the portion 83of the block 42. The pin 93, however, has passed therethrough on theopposite side of the portion 94, a pin 98 which may engage the innerface of the ear 95. By pressing inwardly on the head 99 of the pin 93,the pin 98 may be forced against the ear 95 so as to slide the frame 92transversely to bring the point of the screw 90 into engagement betweenadj acen tthreads of the tap, this screw 90 being so adjusted as to justclear the threads when the frame 92 is in its normally retractedposition. Due to the pivota. mounting of this frame, its upper end maymove in a direction axially of the tap when the screw 90 is projectedinto engagement between the threads so that this screw may properly seatitself between these threads. The parts of this mechanism and thegrinding machine are so proportioned that when the screw 90 is in adefinite location axially, if the indicator 39 on the machine is set tocorrespond with the indicator 69 on the device the grinding wheel 6 ofthe machine properly engages the threads of the tap. The device,therefore, is provided with means for ascertaining this correct positionof the screw in an accurate manner.

As shown more particularly in Figuresl, 3, and 4 the frame 92 isprovided with an upstanding portion 100. Opposite to this portion ispositioned the stem 101 of a length meanning in uznent of any suitabledescription indicated at 102. As shown this instrument is the well known'Waltham indicator by which movements of the stem 101 toward theindicator casing are correspondingly measured on a dial 103 by a pivotedpointer 104. This instrument is designed to show minute movements of thestem 101 and is extremely accurate. especially where these movementsare. very short so that the po nt-er 104 moves a comparatively shortdistance from its Zero point. This indicator is shown as fixed to theblock 42 by means of an ear 105 .projecting therefrom and through whichpasses a fastening screw 106 engaging the block 42. In order to takeadvantage of the extremely accurate index of the instrument 102 when itregisters near the zero mark, the

driving dog 21 having been fixed to the tap 5 in proper angularposition, the screw 90 is brought intoengagement between adjacentthreads in such position that the portion 100 is forced. against thestem 101, thus moving the pointer 104. By turning the hand wheel 75 thecenter 66 is moved to carry the tap axially until the pointer 104reaches its zero posltion. If now the reading of the indicator wheel 69be taken and the indicator wheel 36 I,

of the machine be adjusted to the same indication, the grinding machineis properly ad justed so that the grinding wheel may properly engage thethreads when the tap is placed in position therein with its driving dogin position to be driven from the grinding wheel face plate andremaining fixed to the tap in the relation. determined when the tap wasin the indicating device.

While the indicating device might be de- I ing to this invention havingthus been de I scribed, it should be evident to those skilled in the artthat many changes and modifications may be made without departing fromthe spirit or scope of this invention as defined by the appended claims.

I claim:

1. A. device of the class described comprising a pair of centers betweenwhich a tap may be supported, an abutment ad acent one of said centersagainst which a driving dog secured to a tap supported on said centersmay engage, and indicating means for adjusting said centers and tapaxially to bring the threads of said tap in desired positions.

2. A device of the class described comprising a pair of centers betweenwhich a tap may be supported, an abutment adjacent one of said centersagainst which a driving dog secured to a tap supported on said centersmay engage, an abutment for engagement within a flute of the tap toposition the tap in a proper angular position at which the dog may befixed to said tap, and indicating means for adjusting said centers andtap axially to bring the threads of said tap in desired positions.

3. A device of the class described comprising a pair of centers betweenwhich a tap may be supported, an abutment adjacent one of said centersagainst which a driving dog secured to a tap supported on said-centersmay engage, an element engageable between adjacent threads of the tap,and indicating means for adjusting said centers and tap axially to bringsaid elementto a predetermined position.

4. A device of the class described comprising a pair of centers betweenwhich a tap may be supported, an abutmentadjacent one of said centersagainst which a driving dog secured to a tap supported on said centersmay engage, and an abutment for engage ment within a flute of the tap toposition the tap in a proper angular position at which the dog may befixed to said tap.

5. A device of the class described comprising a pair of centers betweenwhich a tap may be supported, means to hold a tap held between saidcenters against rotation with its flutes definitely positioned withrespect to rotation about the axis of the tap, and means to adjust saidcenters with the tap supported thereby axially to bring the treads ofsaid tap in the desired positions.

6. A device of the class described comprising a pair of centers betweenwhich a tap may be supported, means to hold a tap held between saidcenters against rotation, and means to adjust said centers with the tapsupported thereby axially to bring the threads of said tap in desiredpositions.

7. A device of the class described comprising means for supporting a tapagainst rotation with its axis fixed and with the tap in a definiteposition with respect to rotation about its axis, and means foradjusting certain of said supporting means with the tap supportedthereby endwise to bring the threads of the tap in desired positions.

8. A device or" the class describe-d comprising a support, a pair ofcenters carried by said support and between which a tap may be mounted,a post posi ioned adjacent one of said centers and against which adriving dog engaging a tap supported on said centers may engage, meanscarried by said support and engageable within a flute of said tap tohold it in a definite angular posi tion in which position the dogengaging said post may be clamped to the tap, an indicator, and meansoperatively associated with said indicator for relatively adjusting saidindicator and said centers and tap longitudinally of said ta m saidindicator being constructed to show the relative adjustment of tool andwork holder of a tap finishing machine to properly relate the threads ofsaid tap to the tool of said machine, the tap being rotated in themachine through said dog.

9. A device of the class described conr prising a support, a pair ofcenters carried by said support and between which a tap may be mounted,a post positioned adjacent one of said centers and against which adriving dog secured to a tap supported on said centers may engage, meanscarried by said support for engaging in a flute of the tap to determinean angular position of the tap for clamping the driving dog thereto, aframe movable relative to said support, an element carried by said frameand projectable into mating engagement with the threads of the tap, andindicating means for adjusting said centers carrying the tap axially tobring said element to a definite position with respect to the threads ofthe tap.

10. A device of the class described comprising a support, a pair ofcenters carried by said support, one of said centers being axiallyyieldable from the other center and the other center being axiallyadjustable toward and from said one center, said centers being adaptedto support a tap, a postpositioned adjacent said yieldahle center andagainst which a driving dog secured to a tap supported on said centersmay rest, a frame movable on said support, an element carried by saidframe and project-able into mating engagement with the threads of thetap and movable axially of the tap by movement of said frame, anindicator for showing the position of said element axially of the taprelative to a determined posi ion, and a micrometer indicator forshowing the adj Listed position of said other center and actuable tobring said element to said determined posi tion.

11. A device of the class described comprising means for supporting atap againstrotation about its axis, means including an indicatorresponsive to the axial position of selected tap threads of the tap sosupported, and means for adjusting certain of said supporting means withthe tap supported thereby axially of the tap to bring the indicator to adesired indication, said device includ ing means for indicating theadjusted position of said adjusting means.

In testimony whereof I have aifixed my signature.

RALPH E. FLANDERS.

